"I threw a lot of good cutters in the last few games, it's just that I made a lot of mistakes with it," Pettitte said. "I feel like I actually blew it way out of proportion, to tell you the truth. I had good angle on the ball today and I was glad I was able to give us a good start."
Pettitte had allowed 11 runs (10 earned) over 9 1/3 innings in his previous two starts against the Astros and Athletics, but he limited Kansas City to a Lorenzo Cain RBI groundout and Billy Butler's solo homer over seven innings of five-hit ball.
The Royals were, as usual, the right opponent for Pettitte to snap a three-start winless skid. He improved to 15-3 lifetime against the Royals and is undefeated against Kansas City dating back to a win on Sept. 4, 2000, a span of 14 starts.
"I really don't believe he's forgotten how to pitch, forgotten how to throw a cutter or locate a fastball, any of that," Yankees manager Joe Girardi said. "I always say, when you're old or overweight -- and you don't want to be both -- and you're struggling, people are ready to say, 'Is there something wrong?' No, it's baseball. Everybody struggles."
David Robertson struck out three batters in a scoreless eighth inning to set up Mariano Rivera for his 14th save in as many opportunities.
Salvador Perez reached Rivera for a two-out double and Mike Moustakas made a bid to tie the game with a deep drive to left-center field, but the wind held the ball up long enough for Wells to run it down -- right in the general area of Kauffman Stadium where Rivera's season ended last May.
"I had a feeling," Wells said. "Sometimes you're in the outfield and reading things that go on, and he took some good swings. I knew that the only place he'd most likely be hitting that ball was in the gap. I kind of shaded that way a little bit. I was in the right place."
It marked the 70th victory that Rivera has saved for Pettitte, further extending the all-time Major League record for win-save combinations between any two pitchers. Yankees relievers haven't allowed a run in their last 14 1/3 innings.
"We're letting Mo get into the game in each city that we go to. So far, so good," Wells said.
Pettitte said that he felt some relief in chalking up the victory, which he said came on "a trying day for me," since Pettitte believed that Elliot Johnson fouled a third-inning ball off his foot that was ruled an infield single before coming around to score.
He observed that the ball was spinning sideways, a telltale piece of evidence, and Pettitte also seemed to be alone in complaining that Cain walked on just three balls in the fifth inning in a moment of confusion for the umpires and the scoreboard operator.
"To tell you the truth, I'm just glad," Pettitte said. "Both instances while I was standing out there on the mound, I thought I was losing my mind because I didn't hear anyone else yelling for me."
New York scratched out just enough against Kansas City's James Shields, who allowed three runs (two earned) and six hits in eight innings of work but fell to 7-15 lifetime against his old American League East rivals.
Wells gave the Yankees the lead in the fifth inning with his eighth home run of the season, a shot into the left-field bullpen with Chris Stewart aboard.
"Typical James Shields, changing speeds," Wells said. "He had a good fastball, too, that made his offspeed stuff be even more effective. Luckily, he fell behind me and had to throw fastballs, but he's as good as they come. He's 'Big Game James' for a reason."
The Yankees also put up an unearned run on Shields in the third inning as Chris Nelson stroked a leadoff double and scored on Moustakas' two-out throwing error from third base, which sailed over the head of first baseman Eric Hosmer.
"What can you say? They've been awesome," Pettitte said. "We're playing good ball, I feel like we're confident. We've got a good feeling right now going, and hopefully, we continue to pitch well and keep this stuff going."